Polar Bear families stays in the den until mid-February to mid-April, with the mother maintaining her fast while nursing her cubs on a fat-rich milk. By the time the mother breaks open the entrance to the den, her cubs weigh about 10 to 15 kilograms (22 to 33 lb). This the first time this cub has seen daylight. In the background you can see the ominous reminder to not mess with a bear cub.